DO NOT MERGE [CtsIcuTestCases] Old Android releases can optionally support the new Japanese era

Added @Test to JapaneseTest#TestHeiseiToReiwa to run the test,
the annotation was missing when the test was cherry-picked form upstream

Bug: 131312444
Test: CtsIcuTestCases on old and new system image
Change-Id: Iadc96b33bb11c0716fb9fedd158805b32cf1644f
4 files changed